1. Field of the Invention
This invention relates to chemical remediation of eroded soil or oil- or brine-damaged vegetation and/or soil and more particularly, to a soil remediation composition and method of remediating oil- or brine-damaged soil and vegetation or eroded, sparsely-vegetated or damaged soil by applying the liquid composition to the eroded or damaged soil or damaged soil and vegetation, to both cleanse the brine-or oil-stained soil or soil and vegetation and enhance or accelerate vegetation growth and coverage as the composition percolates through the damaged, eroded or sparsely-vegetated soil In a preferred embodiment the soil remediation composition is characterized by a homogenous aqueous solution of water and selected quantities of urea, dimethylsulfoxide (DMSO), hydrated calcium nitrate and an ionic or non-ionic surfactant such as ether sulfate. The liquid composition is typically sprayed on the damaged, eroded or sparsely-vegetated soil or damaged soil and vegetation, either full-strength or at a selected dilution depending on the degree of soil or vegetation damage or soil erosion, and rapidly penetrates the soil to the vegetation roots to both cleanse the soil and vegetation and promote plant nitrogen assimilation and rapid growth and ground coverage of vegetation. The treated soil is typically seeded to enhance vegetation growth and coverage. A small quantity of dye is typically added to the composition to color and facilitate uniform visual distribution of the composition over the soil or soil and vegetation. In the case of wet oil spills, the soil remediation composition activates hydrocarbon-consuming bacteria, and the treated soil is typically tilled or disced using organic matter such as hay before seeding to aerate the soil, enhance soil recovery and prevent soil erosion. In a second embodiment a liquid calcium solution is mixed with the soil remediation composition for neutralizing ground sodium in the treatment of brine or salt water spills.
In recent years the problem of soil contamination has become increasingly acute, prompting federal state and local governments to mandate clean-up of both accidentally and intentionally contaminated soil. Soil contamination is frequently caused by spillage of petroleum hydrocarbons from oil wells or storage tanks, or leakage of salt water from cross-country piping and storage networks utilized in the oil and process industries. Inland oil spills and leakages can cause localized death of agricultural and natural vegetation and extensive soil damage. Accidental influxes of salts to the soil can devastate most vegetation in the spillage area and stop biological activity in a matter of days, rendering the land unproductive for farming or growth of any type of vegetation. Whether the high influxes of sodium chlorides in the soil result from years of irrigation, brackish water usage or an industrial process-related accident, the results are the same: almost all vegetation within the salt-contaminated area dies, and this in turn may also adversely affect the surrounding ecological balance.
Soil or sand erosion is a problem which is particularly severe in geographic areas having arid climates characterized by little rainfall high solar radiation and high rainwater evaporation rates. Soil erosion is usually caused by loose bonding among soil particles, frequently due to lack of vegetation, and the loose soil, susceptible to being blown by the wind, can contribute to sand storms, dust clouds and sand dune movement. Increasing the natural soil vegetation by enabling the existing sparse vegetation to grow would therefore reverse soil erosion by providing a stabilizing network or scaffold for the soil
2. Description of the Prior Art
Several methods and compositions are known in the art for the remediation, cleansing, stabilizing or conditioning of soil. U.S. Pat. No. 5,615,975, dated Apr. 1, 1997, to Hugh H. Wang, et al., describes a "Method for Remediation of Volatile Organic Contaminated Soils" for detoxification and/or chemical remediation of soil contaminated with volatile organic compounds. The process includes treating the soil with the sodium and calcium salts of naphthalene sulfonates and lignosulfonates, as well as with derivatives and mixtures of these chemicals. Consequently, the volatile organic compounds are forced from the soil since the soil is more attracted to the treatment chemicals than to the volatile organic contaminants. A "Method for Soil Remediation" is disclosed in U.S. Pat. No. 5,634,983, dated Jun. 3, 1997, to Norman Kammeraad. According to the method, an encapsulation solution is applied to soil contaminated with chemicals such as polynucleated aromatics and chlorinated hydrocarbons, in a quantity sufficient to form a saturated mixture of the soil and encapsulation solution. The encapsulation solution is capable of selectively attracting the soil contaminants and contains a non-ionic surfactant material, an anionic surfactant material and water. The mixture is applied to the soil for a time sufficient to permit the contaminants to dissociate from the soil and move into the encapsulation solution. After this occurs, much of the encapsulation solution and associated chemical contaminants can be removed from the soil A "Conditioning Composition and Catalyst for Use Therewith" is detailed in U.S. Pat. No. 5,741,750, dated Apr. 21, 1998, to David A. Hall The composition includes by weight 60-80% a mineral source such as granite, 20-40% basalt, 2-5% a bonding agent such as grey cement, 1-20% a mixed colloidal mineral source such as fine granite dust, and a catalyst provided in the ratio of at least one half liter of catalyst to at least 20 liters of water per 10 tons of composition. The catalyst is composed of water, calcium nitrate, urea, molasses, phosphoric acid and at least one non-ionic surfactant. U.S. Pat. No. 5,811,290, dated Sep. 22, 1998, to Ramesh Varadaraj, et al., describes a "Bioremediation Method of Hydrocarbon Contaminated Soils, Water, and/or Sludge using Urea-Surfactant Clathrates". The composition includes an adduct of urea with a non-ionic surfactant and a phosphorous source. The method provides for the application of a degradation-effective amount of a composition which has an N:P ratio ranging from 10:2 to about 10:0.5. The urea and non-ionic surfactant are present in the adduct in a weight ratio ranging from 98:2 to 75:25. The biodegradation method is carried out by the application of the composition to soil and provides a C:N:P ratio of 100:10:1 to 100:1:001. The C:N:P ratio is based on the weight percent of the hydrocarbon contaminate in the soil, water and/or sludge sites to be treated. "A Method and Composition for Stabilizing Soil and Process for Making the Same" is disclosed in U.S. Pat. No. 5,824,725, dated Oct. 20, 1998, to Shawqui M. Lahalih. The composition is a water-soluble chemical composition for use as a soil stabilizer, conditioner and structuring agent and includes a dispersing agent such as a polyanionic sulfonated urea-melamine formaldehyde condensate; an aggregating agent such as a non-ionic, water-soluble urea-formaldehyde condensate having a relative weight average molecular weights between 400 and 10,000 and a polydispersity between 2.5 and 10; a basic salt-like di-sodium tetra borate and/or a neutral salt such as sodium chloride; and a nitrogen, potassium or phosphorus-containing compound such as potassium nitrate, phosphoric acid or potassium dihydrogen orthophosphate. The composition is sprayed on the top of sand or soil with conventional equipment, to impart significant improvements in the sand or soil mechanical properties and erosion resistance to water and wind. U.S. Pat. No. 5,829,691, dated Nov. 3, 1998, to Roudel Gaudin, discloses a "Method and Apparatus for Washing Soil" which utilizes a water-based surfactant to separate contaminants from soil particles having a size within a predetermined range. After removing the surfactant/contaminant/water mixture from the soil particles, the soil is returned to the remediation site while the mixture is processed through an oil/water separator. Oil and contaminants are then disposed of while the water and surfactant are centrifuged, and the resulting supernatant is recycled back into the apparatus for re-use.
An object of this invention is to provide a composition and method for remediation of damaged or eroded soils.
Another object of this invention is to provide a soil remediation composition characterized by a solution having selected quantities of urea and calcium, which composition is applied to oil-damaged soil, oil-damaged soil and vegetation or eroded soil to cleanse the damaged soil and vegetation and accelerate or enhance vegetation growth and ground coverage on the damaged, eroded or sparsely-vegetated soil.
Still another object of this invention is to provide a soil remediation method for cleansing oil-damaged soil or soil and vegetation and enhancing vegetation growth and ground coverage on the damaged soil or on eroded or sparsely-vegetated soil.
Yet another object of this invention is to provide a soil remediation composition and method for rapidly remediating oil-damaged soil oil-damaged soil and vegetation, eroded soil or soil having sparse vegetation, by cleansing the damaged soil and vegetation and enhancing or accelerating vegetation growth and ground coverage on the damaged, eroded or sparsely-vegetated soil as the liquid composition percolates deep into the soil, which composition in a preferred embodiment is characterized by a substantially homogenous aqueous solution having selected quantities of urea, dimethylsulfoxide (DMSO), hydrated calcium nitrate and an ionic or non-ionic surfactant such as ether sulfate, and is typically sprayed on the damaged vegetation and soil or damaged, eroded or sparsely-vegetated soil.
A still further object of this invention is to provide a soil remediation composition which is capable of rapid and deep penetration of damaged, eroded or sparsely-vegetated soil for delivery of essential nitrogen to soil vegetation in order to facilitate accelerated or enhanced growth and coverage of the vegetation on the soil.
Another object of this invention is to provide a soil remediation composition characterized by a homogenous aqueous solution of urea, dimethylsulfoxide (DMSO), calcium nitrate, ether sulfate and liquid calcium solution for the cleansing and remediation of brine-damaged soil and vegetation.
Yet another object of this invention is to provide a soil remediation composition and method for remediating damaged trees, plants and bushes by applying the composition to the root systems of the damaged trees, plants and bushes.